International Journal of Lightweight Materials and Manufacture最新文献

There is always a vital need for more robust, affordable, and multifunctional materials to satisfy the demands of industrial consumers. Therefore, polymer matrix composites (dual and hybrid matrix) have become popular with multiple fillers to meet these needs. Graphene nano-platelet (GNP) and Carbon fibre (CF) are popular among those fillers due to their superior properties, such as good mechanical, thermal, and electrical properties. Low density polyethylene (LDPE), Polystyrene (PS), GNP, and CF are popular and heavily used in the packaging, automotive, and aerospace industries. However, it would be good to look at how these areas have evolved over the last few decades. Hence, this review focuses on a comparison of LDPE and PS as a matrix and GNP and CF as a filler, considering the content that determines the overall performance of blends and composites. The literature was screened for the last few decades. The blends and/or composites produced by a twin-screw extruder were included. A total of 1628 relevant papers were retrieved from all databases. Based on the review, it was deduced that more research should be needed in areas such as the aerospace industry to identify optimum content. Most of the analysis showed that factors such as filler surface area, dispersion, and content affect overall blends and composites' performance in terms of mechanical properties, especially elastic modulus and tensile strength, and other properties. Based on the review, it was realised that using 20 and 30 wt%, 2 and 30 wt%, 2 and 4 wt%, and 20 and 30 wt% filler was the most common combination giving the optimum content for LDPE, PS, GNP, and CF, respectively. EMS and TSH changes of the composites were calculated according to their optimum content. Overall, LDPE and PS are good in packaging areas, but their mechanical properties still need to be improved for use in industries such as automotive, aerospace etc. Due to the advantages of GNP and CF, they are used in different applications, such as electrical devices, medical tools, and automobile vehicles. However, these properties are affected easily by interfacial adhesion, dispersion, and aggregation. Many researchers have searched these parameters and analysed how to prevent the negative effects of these parameters. In conclusion, this review will be helpful for researchers and industrial people to be aware of the state-of-the-art of carbon-based composites and the evolution of LDPE, PS, GNP, and CF.

The examination of the machining of 7075-T6 aluminum alloy polymer mold cavities using Taguchi optimization and analysis of variance is presented in this paper. This study identified the best CNC milling cutting parameters and used a mathematical model to quantify the surface roughness of the machined cavities. The findings showed that while using a flat endmill, the spindle speed multiplied by feed rate contributed 28.01% to surface roughness, and when using a ball endmill, the squared depth of cut contributed 41.27%. Using both flat and ball endmills, the depth of the cut contributed 98.53% to the material removal rate. A refined second-order linear regression model was employed to forecast the endmill-machined surface roughness. The Warp Surf Portable tester measured values that were outside the error range of approximately 0.257% and 2.8%, respectively, for the expected values. Surface roughness has a 99.97% correlation coefficient in the regression model, indicating a very significant link. Additionally, the study improved the cutting parameters for a ball endmill, which were 3005 Rpm, 726.7 mm/min, and 0.43 mm, and for a flat endmill, these were spindle speed (2500 Rpm), feed rate (650 mm/min), and axial cut depth (0.5 mm). The outcomes demonstrated how well the techniques enhanced mold cavity machining and cost estimation using Ra and MRR data. Consequently, these results can be applied to future academic studies and industrial applications.

Additive Manufacturing (AM) technology is recognized as a pivotal direction for future technological and industrial advancement. Nevertheless, inherent to the manufacturing process are defects such as pores, inclusions, lack of fusion, and layering, which pose significant threats to product quality and safety, thereby serving as significant obstacles to the widespread adoption of additive manufacturing technology. Consequently, in recent years, non-destructive testing techniques for additive manufacturing products have gained considerable attention in research.

This paper focuses on components manufactured using the Laser Metal Deposit (LMD) process with AlSi10Mg material. Through a combination of finite element simulations and experimental analysis, this study compares and analyzes the propagation of laser ultrasound within AM components. By examining the characteristics of shear wave reflection signals from internal defects in AM components, a defect quantification method based on a laser ultrasonic (LU) inspection system is proposed. The research findings indicate that this method is capable of detecting sub-millimeter-level internal defects within AM components. Extracting the shear wave reflection signals from defects, enables quantitative assessment of the location and depth of internal defects in AM components.

Magnesium (Mg) alloys are becoming popular in lightweight manufacturing due to their low density and high specific strength. However, insufficient slip systems result in poor plasticity of Mg alloys at room temperature. Therefore, an ultrasonic energy field combined with thermal field is introduced to assist the deformation of AZ31 Mg alloy to improve its plasticity. Firstly, ultrasonic vibration (UV)-assisted tensile tests at different temperatures (130–150 °C) are conducted to investigate the effect of UV on material behaviour and the activation of dynamic recrystallization (DRX). Then, the influences of UV on the mechanical properties and microstructure of the material at 150 °C are investigated by varying the parameters of ultrasound amplitude, strain rate, and vibration interval. The results reveal that applying UV can activate DRX at a relatively lower temperature compared with that without UV. Superimposing a certain amount of ultrasonic energy on this material at warm conditions reduces flow stress and increases elongation. In the intermittent ultrasonic vibration (IUV) tests, the DRX percentage and elongation first increase and then decrease as the vibration interval increases. The elongation of specimens with appropriate vibration intervals even exceeds that of specimens with continuous ultrasonic vibration (CUV). However, CUV is more effective than IUV in reducing ultimate tensile strength at different amplitudes or strain rates.

The utilization of Aluminum hollow panels enhances structural strength while simultaneously ensuring a lightweight and efficient use of materials. During their application, these panels necessitate a welding process that is susceptible to porosity due to the disparity in hydrogen gas solubility between liquid and solid aluminum. Solid-state welding techniques, such as Friction Stir Welding (FSW), have proven to be effective and appropriate solutions for overcoming this issue. However, due to the thickness of the hollow panels, FSW process is unfeasible as it requires welding on both sides, resulting in prolonged production times. Consequently, the development of a one-step double-acting FSW technique becomes necessary, involving the simultaneous utilization of two tools. The usage of two tools introduces two sources of friction-stir forces, heat, and axial forces, demanding an assessment of the novel response from the specimens. This research aims to analyze the effect of a specific parameter, namely the tool rotation speed, within the one-step double-acting FSW process on the physical and mechanical properties of the AA6061 hollow panels. The One-Step Double-Acting FSW process involved conducting variations in the tool rotation speed on both sides of the welds. Specifically, for the 4G weld position (underside of the workpiece with an overhead weld position), speeds of 1200, 1500, and 1800 rpm were employed. Meanwhile, a consistent rotation speed of 1500 rpm was maintained for the 1G weld position (overside of the material with a flat weld position). The transverse speed and tilt angle are set at 30 mm/min and 2°, respectively. Elevating the tool rotation speed results in increased hardness, load capacity, and bending strength of the weld joints. The specimen subjected to the highest rotational speed (1800 rpm) exhibits the most exceptional mechanical properties, including a hardness of 73.46 HVN, load capacity of 18.47 kN, and bending strength of 60.56 MPa.

This article contains the results of research on the development of a C_f/C-UHTC carbon fabric composite based on a viscose precursor and a combined matrix consisting of partially sintered ceramics in a system consisting of HfC–HfB₂–NbC–NbB₂–TiC–TiB₂–B₄C–SiC, amorphous carbon, and pyrocarbon. The SiC fraction does not exceed 8.5–9.0 wt%. In its initial state, the composite has open porosity, with apparent and true densities of 18–22%, 2.25–2.29 g/cm³ and 2.79–2.91 g/cm³, respectively. The bending strength and the elasticity modulus are 27.8 ± 0.7 MPa and 7.8 ± 0.2 GPa, respectively, and the fracture strain is 0.85 ± 0.05%. The tests for resistance to oxidation and ablation were carried out in a gas dynamic flow regime and non-equilibrium air plasma heating at flow rates of 4.5–4.8 km/s and breaking enthalpy of 45–50 MJ/kg. Heating was performed in the temperature range T_w = 1400–2700 °C at the critical point on the front surface of the samples. The average linear ablation rate and mass loss rate of the composite are 6.3 ± 0.3 μm/s and 6.22 ± 0.44 mg/s. The estimated value of the conductivity factor is 0.280–0.285 W/(m K). The performance ability of the composite arises from the formation and evolution of a passivating heterogeneous oxide film consisting mainly of titanium niobate Ti₂Nb₁₀O₂₉, mixed solutions of Hf_1−xTi_xO₂, (Ti_1−xHf_x)_1−yNb_yO_z and (Ti_1−xHf_x)NbO₄ with broad homogeneity ranges, and also encapsulated carbide and boride particles. It is shown that the oxidation resistance of the composite increases as a result of the transition through a number of phases into a liquid state as the working temperature increases.

The results of studies technological processes for obtaining welding wire from alloys of the Al–Mg system with a scandium content of 0.12 (alloy 1580) and 0.25 wt % (alloy 01570) presented. A feature of the technology is the production of a billet for further cold deformation by an energy-efficient method of ingotless rolling-extrusion (IRE). It was found that hot-extruded rods from the investigated alloys obtained by the IRE method have the required level of plastic and strength properties necessary for further cold deformation up to 80%. Thermomechanical processing of hot-extruded rods manufactured by IRE have been developed and experimentally tested, which made it possible to obtain a billet with a square side of 5 × 5 mm by sectional rolling and wire with a diameter of 3 mm by drawing. Studies of the structure and mechanical properties of deformed semi-finished products have shown that the developed modes make it possible to obtain a welding wire from the investigated alloys that meets the requirements of current standards. Studies of the operational properties of the obtained welding wire were carried out. It was found that alloy 1580 with a minimum content of scandium (0.12 wt %) is not inferior to alloy 01570 in terms of corrosion resistance and weld quality. Developed technology for the production of welding wire from alloys of the Al–Mg system with different scandium content can be recommended for industrial use. It is advisable to implement alloy 1580, which has a lower cost compared to alloy 01570.

Incorporating sustainability into Concrete-Filled Steel Tubular (CFST) columns' optimization can enhance efficiency and sustainability in construction. Discrepancies in international standards for ultimate load capacity computation in compact CFST columns under eccentric loading, particularly with lightweight high-strength concrete, pose challenges. This research compile a dataset of compact CFST columns, evaluating design codes (AISC 360-16, Eurocode 4) against experimental results. Besides, a comprehensive finite-element model predicts compact CFST column performance, investigating axial force-moment (P-M) interaction behavior with respect to the material strength ratio ($f_y$/$f_c^{\prime }$). In the second phase of the study, an ANN model, incorporating input parameters, estimates axial load capacity, facilitating multi-objective optimization for optimal CFST column geometry. The results confirmed that Eurocode 4 outperforms AISC 360-16 in experimental axial capacity predictions ($N_{uc}$/$N_{uc,theoretical}$) where, the mean and standard deviation for Eurocode 4 were estimated at 1.07 and 0.22, respectively, compared to 1.21 and 0.29 for AISC 360-16. Besides, statistical metrics confirm the precision of the ANN model, particularly with high-strength concrete, promising efficiency in future computational intelligence-based structural design platforms.